* Atri Sharma (atri.j...@gmail.com) wrote: > Isnt using a user given value for selectivity a pretty risky situation as > it can horribly screw up the plan selection? > > Why not allow the user to specify an alternate plan and have the planner
Uh, you're worried about the user given us a garbage selectivity, but
they're going to get a full-blown plan perfect?
> assign a higher preference to it during plan evaluation? This shall allow
> us to still have a fair evaluation of all possible plans as we do right now
> and yet have a higher preference for the user given plan during evaluation?
What exactly would such a "preference" look like? A cost modifier?
We'd almost certainly have to make that into a GUC or a value passed in
as part of the query, with a high likelihood of users figuring out how
to use it to say "use my plan forever and always"..
Thanks,
Stephen
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